Question

solve x²-8x - 15=0 and correct to two decimal
places.​

Answer 1

Step-by-step explanation:

${x}^{2} - 8x - 15 = 0$

• 5+3=8
• $5 \times 3 = 15$

${x}^{2} - 5x - 3x - 15 = 0$

(x-5)+3(x-5)=0

(x-3) (x-5)=0

x-3=0

x=+3

x-5=0

x=+5

check:

(x-3) (x-5)=0

x(x-5)-3(x-5)=0

${x}^{2} \: - 5x - 3x - 15 = 0$

${x}^{2} - 8x - 15 = 0$